The effect of tangential acceleration can be either positive or negative on the shaft. If the head is still accelerating (gaining speed) just before impact, the shaft will bend backwards (shaft lag) thus reducing the loft and offsetting the effect of centrifugal acceleration which always wants to bend the shaft forward before impact. If the golfer slows the club and losses tangential acceleration before impact the shaft will bend forward (shaft lead) and increase the launch angle.
shaft bending | Golf Monthly
|
